/* the Music Player Daemon (MPD)
 * Copyright (C) 2008 Max Kellermann <max@duempel.org>
 * This project's homepage is: http://www.musicpd.org
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

/*
 * Maps directory and song objects to file system paths.
 */

#include "mapper.h"
#include "directory.h"
#include "song.h"
#include "path.h"
#include "conf.h"

#include <glib.h>

#include <assert.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>

static char *music_dir;
static size_t music_dir_length;

static char *playlist_dir;

/**
 * Duplicate a string, chop all trailing slashes.
 */
static char *
strdup_chop_slash(const char *path_fs)
{
	size_t length = strlen(path_fs);

	while (length > 0 && path_fs[length - 1] == G_DIR_SEPARATOR)
		--length;

	return g_strndup(path_fs, length);
}

static void
mapper_set_music_dir(const char *path)
{
	int ret;
	struct stat st;

	music_dir = strdup_chop_slash(path);
	music_dir_length = strlen(music_dir);

	ret = stat(music_dir, &st);
	if (ret < 0)
		g_warning("failed to stat music directory \"%s\": %s",
			  music_dir, g_strerror(errno));
	else if (!S_ISDIR(st.st_mode))
		g_warning("music directory is not a directory: \"%s\"",
			  music_dir);
}

static void
mapper_set_playlist_dir(const char *path)
{
	int ret;
	struct stat st;

	playlist_dir = g_strdup(path);

	ret = stat(playlist_dir, &st);
	if (ret < 0)
		g_warning("failed to stat playlist directory \"%s\": %s",
			  playlist_dir, g_strerror(errno));
	else if (!S_ISDIR(st.st_mode))
		g_warning("playlist directory is not a directory: \"%s\"",
			  playlist_dir);
}

void mapper_init(void)
{
	const char *path;

	path = config_get_path(CONF_MUSIC_DIR);
	if (path != NULL)
		mapper_set_music_dir(path);
#if GLIB_MAJOR_VERSION > 2 || (GLIB_MAJOR_VERSION == 2 && GLIB_MINOR_VERSION >= 14)
	else {
		path = g_get_user_special_dir(G_USER_DIRECTORY_MUSIC);
		if (path != NULL)
			mapper_set_music_dir(path);
	}
#endif

	path = config_get_path(CONF_PLAYLIST_DIR);
	if (path != NULL)
		mapper_set_playlist_dir(path);
}

void mapper_finish(void)
{
	g_free(music_dir);
	g_free(playlist_dir);
}

bool
mapper_has_music_directory(void)
{
	return music_dir != NULL;
}

char *
map_uri_fs(const char *uri)
{
	char *uri_fs, *path_fs;

	assert(uri != NULL);
	assert(*uri != '/');

	if (music_dir == NULL)
		return NULL;

	uri_fs = utf8_to_fs_charset(uri);
	if (uri_fs == NULL)
		return NULL;

	path_fs = g_build_filename(music_dir, uri_fs, NULL);
	g_free(uri_fs);

	return path_fs;
}

char *
map_directory_fs(const struct directory *directory)
{
	assert(music_dir != NULL);

	if (directory_is_root(directory))
		return g_strdup(music_dir);

	return map_uri_fs(directory_get_path(directory));
}

char *
map_directory_child_fs(const struct directory *directory, const char *name)
{
	char *name_fs, *parent_fs, *path;

	assert(music_dir != NULL);

	/* check for invalid or unauthorized base names */
	if (*name == 0 || strchr(name, '/') != NULL ||
	    strcmp(name, ".") == 0 || strcmp(name, "..") == 0)
		return NULL;

	parent_fs = map_directory_fs(directory);
	if (parent_fs == NULL)
		return NULL;

	name_fs = utf8_to_fs_charset(name);
	if (name_fs == NULL) {
		g_free(parent_fs);
		return NULL;
	}

	path = g_build_filename(parent_fs, name_fs, NULL);
	g_free(parent_fs);
	g_free(name_fs);

	return path;
}

char *
map_song_fs(const struct song *song)
{
	assert(song_is_file(song));

	if (song_in_database(song))
		return map_directory_child_fs(song->parent, song->url);
	else
		return utf8_to_fs_charset(song->url);
}

char *
map_fs_to_utf8(const char *path_fs)
{
	if (music_dir != NULL &&
	    strncmp(path_fs, music_dir, music_dir_length) == 0 &&
	    path_fs[music_dir_length] == '/')
		/* remove musicDir prefix */
		path_fs += music_dir_length + 1;
	else if (path_fs[0] == '/')
		/* not within musicDir */
		return NULL;

	return fs_charset_to_utf8(path_fs);
}

const char *
map_spl_path(void)
{
	return playlist_dir;
}

char *
map_spl_utf8_to_fs(const char *name)
{
	char *filename = g_strconcat(name, PLAYLIST_FILE_SUFFIX, NULL);
	char *path;

	if (playlist_dir == NULL)
		return NULL;

	path = g_build_filename(playlist_dir, filename, NULL);
	g_free(filename);

	return path;
}